Employee of a Russian Anti-Plague Lab Dies of Pneumonia, Sparking Concerns Over the Disease Behind the Black Death. Here's What to Know

A 28-year-old laboratory technician at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East in Russia fell ill and died of pneumonia last week, sparking concerns that she may have had the rare but deadly pneumonic plague. The exact circumstances of the employee’s sickness are still unclear as conflicting reports have emerged from the country. One Russian news outlet claimed that the worker, named Darya Shipilova, may have contracted pneumonia from a broken test tube containing plague samples, while another said that she contracted the disease after a trip to Thailand.

There have also been concerns that the woman worked in a bioterrorism unit, though this has not been confirmed. Dozens of people have been quarantined in the region of Siberia, although the country’s national health agency said that none of Shipilova’s close contacts tested positive for the plague, according to an October 6 statement from the World Health Organization (WHO). No cause of death has been confirmed at this point, and the agency estimates the risk to the global public is low.

Here’s what you should know about the disease at the center of the story. The plague is an infection caused by the bacterium Yersinia pestis. The most common forms of plague are bubonic, pneumonic and septicemic.

According to the Centers for Disease Control and Prevention (CDC), pneumonic plague is the most serious form of the disease, and it’s the only one that can spread from person to person. However, it’s also the least common in nature. Pneumonic plague occurs when Y. pestis spreads to the lungs of a person with untreated bubonic or septicemic plague, or when a person inhales droplets from a person or animal infected with pneumonic plague.

Symptoms include fever, headache, weakness and a quickly developing pneumonia with shortness of breath, chest pain, cough and even bloody or watery mucus. The disease progresses rapidly—symptoms can start as soon as one day after infection, according to the WHO. And once they set in, the illness can be fatal within 18 to 24 hours.

That’s also why it’s categorized as a “Category A” bioterrorism agent by the CDC. A roughly two-week course of antibiotics can treat the plague, reports CNN’s Jen Christensen. The sooner patients start the regimen, the better.